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l^frl Agriculture 


Research Direction generate 
Branch de la recherche 

Technical Bulletin 1991-9E 

Plants of the prairie 
aquatic ecosystems 

■ *■ Agriculture 

■ Ti Canada jun _ ^ ]Qg| 


Library / Bibliotheque, Ottawa K1A 0C5 

C Cft _ cj 



Digitized by the Internet Archive 
in 2013 

Plants of the prairie 
aquatic ecosystems 

Research Station 
Lethbridge, Alberta 

Technical Bulletin 1991-9E 

Lethbridge Research Station Contribution No. 15 

Research Branch 
Agriculture Canada 

Copies of this publication are available from 

Dr. J.R. Allan 

Soil Science Section 

Research Station 

Research Branch, Agriculture Canada 

P.O. Box 3000, Main 

Lethbridge, Alberta 

T1J 4B1 

Produced by Research Program Service 

® Minister of Supply and Services Canada 1991 
Cat. No. A54-8/1991-9E 
ISBN 0-662-18839-X 

Cover illustration 

The dots on the map represent 
Agriculture Canada research 





Group I. Submergent aquatic plants 8 

Group II. Floating-leaved aquatic plants 17 

Group III. Free-floating aquatic plants 21 

Group IV. Emergent aquatic plants 23 


- 11 - 


Native and introduced aquatic plants have been surveyed in southern Alberta 
and Saskatchewan since 1966. The generally accepted belief is that diversity 
in plant species increases as one moves south toward the tropics (equator). 
However, the wide range of aquatic environments, natural and man-made, has 
created favorable habitats for many submergent, floating-leaved, free-floating 
and emergent aquatic plants. This publication lists the taxa of the aquatic 
vascular plants found in Prairie aquatic ecosystems, provides a description of 
the common and less common species and one or more characteristics of the 
dominant species found in the various natural and man-made environments. 


Les plantes aquatiques indigenes et introduites font l'objet d'un releve dans 
le sud de 1' Alberta et de la Saskatchewan depuis 1966. II est generalement 
accepte que la diversite des especes vegetales s'accroit au fur et a mesure 
que l'on avance vers le sud et s'approche des Tropiques (equateur). 
Toutefois, la gamme etendue de milieux aquatiques, naturels et artificiels, a 
cree des habitats favorables a de nombreuses plantes aquatiques immergees, 
flottantes enracinees et non enracinees et emergentes. Cette publication 
presente une liste des taxons des plantes vasculaires aquatiques que l'on 
retrouve dans les ecosystemes aquatiques des Prairies, une description des 
especes courantes et moins communes ainsi qu'au mo ins une caracteristique de 
l'espece dominante dans les divers milieux naturels et artificiels. 


Through the ages vascular plants have spread over the land, adapting 
themselves to the mechanical and physiological rigors of terrestrial life. 
They escaped from aquatic environments and developed the seed-producing 
habit. The most successful plants no longer needed water as a medium for 
ovule fertilization and spread rapidly over the land surface to replace the 
gymnosperms as the dominant vegetation. Yet, despite this triumphant 
occupation of the land, a few angiosperms returned to the aquatic 
environment of lakes and rivers; some even returned to the sea. Here they 
live and reproduce in a partly or wholly submerged state. A liberal 
estimate of the number of plants in this specialized minority is unlikely to 
exceed 1% of the angiosperms and 2% of the pteridophytes. These vascular 
hydrophytes comprise 33 families, of which 30 have fewer than 10 genera 
each, 17 families are monogeneric, and 3 families are monotypic. This 
minority embraced the change to aquatic life so thoroughly that some had 
their leafy shoots completely submerged in water. Some ceased to take root 
in the substratum and spent their entire vegetative life floating freely in 
the water. But most of these vascular hydrophytes have retained the 
advanced reproductive methods of their terrestrial ancestors. Regardless of 
how deeply these plants grow underwater, most aquatic plants still strive to 
push their flowers to the surface of the water for pollination by insects or 
the wind. 

The close relationship between the aquatic vascular plants and the aquatic 
environment is of prime importance to these plants and to other smaller 
plants and animals that depend on them for support, protection and food. 
Aquatic vascular plants are only a small part of the larger and more complex 
aquatic ecosystem, which can be regarded as the product of an interaction 
between the environment (the physical and chemical factors) and the plant 
community (the living component). This dynamic interaction involves the 
flow of energy through the aquatic system and a series of nutrient cycles. 
The trophic nature and biological productivity of the aquatic ecosystem in 
turn are the result of the specific geographical location and the human, 
geological, topographic and climatic factors acting on the ecosystems. 

Currently on the Canadian prairies there are 630,000 ha of land under 
irrigation: 506,000 ha in Alberta, 100,000 ha in Saskatchewan, and 24,000 
ha in Manitoba. Excessive growth of rooted, submerged, aquatic macrophytes 
is a serious problem in Prairie irrigation systems. In Alberta, more than 
12,500 km of primary, secondary and on-farm irrigation and drainage canals 
are infested with nuisance algae and aquatic weeds. Water is delivered to 
Alberta land through an irrigation distribution system in which 90% of the 
canal system is earth-lined. Scattered throughout the system are numerous 
on-stream irrigation storage reservoirs. Aquatic macrophyte growth in 
southern Alberta canals can impede the flow of irrigation water by as much 
as 91% of design capacity by mid-August. The entire system is a prime 
habitat for the excessive growth of numerous aquatic plant species. 

Field surveys over the last 20 years at the Lethbridge Research Station have 

identified a number of aquatic plant infestation characteristics, which has 

enabled the effective implementation of an integrated aquatic vegetation 
management program. 

- 2 - 

Previous studies have shown that the carrying capacity of the irrigation 
canal, the velocity of the moving water, and the water chemistry such as the 
total solids, dissolved total solids, and silt content of the irrigation 
canal generally determine the aquatic weed species growing in the canal 
(Table 1). The reduced day-length (photoperiod) available to rooted, 
submerged, aquatic macrophytes is related to the north-south or east-west 
orientation of a canal. Preliminary studies on radiant energy indicate that 
the reflection and penetration of radiant energy by the water in the canal 
may influence the occurrence of native aquatic plant species such as 
northern and green water milfoil plants ( Myriophyllum spp.). Previous 
studies with aquatic herbicides applied at different times during the 
aquatic weed-growing season have demonstrated a marked difference in 
effectiveness and plant susceptibility. This was thought to be due to 
changes in water temperature, water chemistry, silt loading, and degree of 
vegetative plant development. However, studies during the summer of 1989 
documented the naturally occurring seasonal appearance and changes in growth 
habit of various native aquatic plant species during the irrigation season. 
This new information will help establish better criteria for the selection 
of effective chemical and biological aquatic plant management techniques. 

Aquatic vascular plants may be described by several convenient technical 
terms. Aquatic habitats cannot always be sharply distinguished from 
terrestrial ones. In most climates the seasonal fluctuation of the water 
table means that in the spring and fall there may be standing water, which 
dries out in summer. Also, there is often no abrupt change from land to 
water, but rather a gradual transition from dry to waterlogged to submerged 
soils. In this publication, a 'vascular hydrophyte' is defined as a plant 
growing in water, in soil covered with water, or in soil that is usually 
saturated with water. The different life forms of vascular hydrophytes can 
then be divided into four general categories (from Sculthorpe, 1967): 
submergent (Fig. 1), floating-leaved (Fig. 2), free-floating (Fig. 3), and 
emergent (Fig. 4) aquatic plants. This classification is intended to 
provide a guide for the identification of vascular hydrophytes found in 
Western Canada. 

Group IV 


High water • 

Average water 
Low water 

- 3 - 

Table 1. Rooted, submerged, aquatic macrophytes occurring in 
southern Alberta irrigation canals. 

Canal flow rate (m 3 /s) 

1.5-10.0 10.0-28.5 >28.5 
Species (50-350 cfs) (350-1000 cfs) (>1000 cfs) 

Ranunculus trichophyl lus 
(water crowfoot) 

Chara vulgarus 

(stonewort or muskgrass) 

Zannichel lia palustris 
(horned pondweed) 

Potamoqeton friesii 
(Fries' pondweed) 

Potamoqeton fol iosus 
(leafy pondweed) 

Potamoqeton strictifolius 
(straight-leaf pondweed) 

Hippuris vulgaris 
(mare's-tai 1) 

Myriophyllum heterophyllum 
(variable leaf milfoil) 

Myriophyl lum exalbescens 

(common or northern water milfoil) 

Myriophyllum verticillatum 
(green water milfoil) 

Potamoqeton pusi 1 1 us 
(small -leaf pondweed) 

Al isma qramineum 

(narrowleaf water plantain) 

Potamoqeton richardsoni i 
(Richardson's pondweed) 

Potamoqeton pectinatus 
(sago pondweed) 

Potamoqeton zosteriformis 
(flat-stemmed pondweed) 

Potamoqeton vaqinatus 

(giant or sheathed pondweed) 

- 4 

Figure 1. Life cycle of the submergent rooted aquatic macrophyte, 
Myriophyl Turn vertici 1 latum . A. Vegetative shoot of water milfoil. 
B. Mature plant of water milfoil showing the production of overwintering 
buds or turions at the tip of each vegetative branch. C. Appearance of 
the plant in flowing water. D. Appearance of the plant in standing water 
with other rooted aquatic plant species. E. Stem fragments showing root 
development at the base of the shoot. F. Leaf structure of overwintering 
turion. G. Typical leaf structure of water milfoil plant. H. Flower 
head at the surface of the water. I. Flower head extending into the air 
for wind pollination. J. Details of flower head showing characteristic 
flower bracts used to identify Myriophyl lum spp. K. Details of 
Myriophyl lum spp. turions. 

~ A 

Figure 2. Life cycle of the floating-leaved aquatic macrophyte, Nymphaea 
odorata. A. The typical plant growing under greenhouse or ornamental water 
garden conditions. B. Aerial view of water lilies growing in lakes in 
northern Alberta. C. Crown of water lily plant showing vegetative shoots. 
D. Tuber of water lily plant showing extended leaf petiole. E. Water lily 
planted in tub in an ornamental water garden. F. Detail of floating leaf 
of water lily plant. G. Water lily plant with fully open flower. H. 
Detail of the opened water lily flower. 

6 - 


Figure 3. Life cycle of the free-floating aquatic macrophyte, Utricularia 
vulgaris . A. Vegetative shoot completely lacking roots but possessing 
small black bladders that assist in the trapping of aquatic organisms for 
food. B. Overwintering turion of the common bladderwort. C. The 
expansion of the turion in the spring when water temperature reaches 15°C. 
D. Details of leaf structure showing the small bladders. E. The free- 
floating bladderwort along the shore of a stock-watering pond showing the 
showy flower. F. Details of the flower head. G. Typical habitat of the 
common bladderwort showing the numerous flower heads. 

- 7 - 

Figure 4. Life cycle of the emergent aquatic macrophyte, Typha 1 at i folia . 
A. Colony of cattails growing at the edge of a pond. B. Underground 
rhizome system showing two vegetative shoots and the root system. C. Young 
cattail shoots in 10-20 cm of water. D. Mature plant showing leaf 
formation and structure. E. Crown of a mature plant with root system. 

F. Early inflorescence stage or 'window' when plants are most susceptible 
to chemical control showing male flowers above the female flowers. 

G. Young flower head with developing female portion and the male portion 
above after the pollen is shed. H. Mature cattail head just beginning to 
shed the wind-disseminated seeds. I. Exploded cattail seed head with 
winged seeds ready to be wind-blown to potential marsh sites. 

- 8 


Group I. Submergent aquatic plants 

A. Plants with feather-like, limp leaves on flexible underwater stems 
Stem tips often extend above the surface of the water. 

northern water mi' foi 

Myriophyllum exalbescens Fern. 



Flower spike: 

British Columbia to Manitoba. Usually in calcareous 
still water, very slow streams, ponds, pools, and 

Perennial, submerged, with smooth, simple stems. 
Reddish-purple when fresh, turn white when dry. 

Finely dissected into 6-10 pairs, 1-3 cm long; 3-5 
segments arranged in whorls around the stem. 

Three, arranged around the stem with upper flowers 
male and lower flowers female. Leaf-like bracts 
shorter than the flowers. 

green water mi lfoi 1 

Myriophyllum vert ici 1 latum L, 


Flower spike: 

British Columbia to Manitoba. In shallow water with 
high clay and calcium content. 

Similar to northern water milfoil. 

Finely dissected into 9-15 pairs, 1-4 cm long; 4-5 
segments arranged in whorls around the stem. 

Three in number, arranged around the stem. Bracts 
deeply divided and much longer than the flowers. 

Plants with needle-like to oval, paired, or bunched leaves on flexible 
underwater stems. 

1. mare's-tail 

Hippuris vulgaris L. 

British Columbia to Manitoba. In shallow pools and 
along margins of lakes, streams, and ponds. 

- 9 - 




Perennial, upright, and at least partly out of the 
water. Stems erect, hollow, rarely forked, smooth, 
and cylindrical arising from creeping rhizome. 

Two types: submerged ones delicate, linear, 2-4 cm 
long, slender, narrowing to a top in whorls of six 
or more. Aerial leaves much shorter, 0.5-1.0 cm 
long, thicker, and firmer than submerged ones. 

Appear in axils of upper aerial leaves. 

2. water starwort 




Callitriche palustris L. 

British Columbia to Manitoba. In shallow quiet 
ponds and lakes with high calcium content. 

Low perennial growing submerged or partly floating 
along muddy shores in clear water. 

Lower submerged leaves pale green without a petiole, 
linear, 10-15 mm long, 1-nerved. Transitional 
leaves lance-shaped below water surface and 
spatulate above. Floating leaves petioled, shaped 
like a spatula, 5-10 long, crowded at stem tip. 

Have paired bracts in axils of upper leaves. 

horned pondweed 



Zannichellia palustris L. 

British Columbia to Manitoba. In ponds, ditches, or 
very slow-moving streams. 

Submerged, with slender, hair-like, branched stems. 

Submerged, long, needle-like but flat, 2-10 cm long 
and 0.2-0.5 mm wide, whorled with 1 nerve with a 
sharp tip at the apex. 

Curved, often with teeth directed outward on a short 
stalk. Prominent beak opposite the stalk. 

4. Canada waterweed 


Elodea canadensis (Michx.) Planchon 

British Columbia to Manitoba. In quiet lakes and 
ponds with high calcium content. 

Submerged, freely branching, forming large masses in 
the water. Stems slender with numerous whorls of 
leaves and often rooting at the nodes. Root system 
very fibrous. 

- 10 - 



Whorled, without petioles, linear, 1.2-4 mm wide, 
usually minutely toothed with 1 nerve. 

Male and female flowers borne on separate plants 
(dioecious) with flowers falling away rapidly. Male 
flowers in long stalks. 

5. marsh-purslane 



Ludwiqia palustris (L.) Ell. var. americana 

British Columbia to Manitoba. Usually on muddy 
banks or pond edges. 

Has creeping, slender stems sprawling on wet ground 
or partly underwater. Occasionally in clear springs 
or spring-fed streams. 

Submerged leaves opposite, up to 6 cm long, thin, 
diamond shape with a slender petiole. 

Very small, without petioles, on short stalks in the 
leaf axils. 

C. Plants with clustered branches on fine-forked, bladderless, usually limp 
leaves on flexible underwater stems. 

muskgrass Chara sp. 

Range: British Columbia to Manitoba. 

Plant: A non-vascular plant belonging to the algae family. 
The plant is very rough, harsh, generally encrusted 
with lime (CaC0 3 ), varying with the degree of water 
hardness in which it grows. Each joint of the stem 
consists of a single cell. Whorled branches appear 
at nodes, which appear to be leaf-like. Oogonium 
containing fertilized egg cell appears as a bright 
orange structure in the axils of the stem-like 
branches. Fresh plants have strong fishy smell. 

white water buttercup 

Ranunculus circinatus var. subriqidus 


British Columbia to Manitoba. In ponds, ditches, 
streams, and pools. 

Perennial, submerged with smooth, elongated, 
branched stems rooting at the lower nodes. 

- 11 - 



Submerged, 1.0-2.5 cm long, finely dissected into 
thread-like division with distinct clasping petiole 
sheath at the base. 

Solitary with five broad, conspicuous, white petals, 
each with a nectariferous spot or pit at the base of 
the petal . 

yellow water buttercup 

Ranunculus purshii Rich. 




British Columbia to Manitoba. In shallow lakes, 
along stream borders and on mud marsh flats. 

Perennial, submergent or inhabiting wet marshy 
ground. Stems smooth, trailing roots at the lower 

Submergent leaves delicate, circular or kidney- 
shaped in outline, 3-5 cleft into wedge-shaped 
divisions. Emergent or floating leaves smaller, 
thicker with wider lobes. Both types on petioles. 

Solitary with five circular yellow petals with a 
nectariferous spot at base. 





Ceratophyl Turn demersum L. 

British Columbia to Manitoba. Widespread. 

Submerged, herbaceous with freely branching stems 
having leaves crowded at the tips ("coontail" 
effect). Plants often form large dense masses. 

Finely divided, rigid or somewhat brittle leaves are 
cut into 2-4 forked divisions and are produced in 
whorls at stem nodes. Individual divisions have 
tooth-like projections along one side. 

water marigold Meqalodonta beckii (Torr.) Greene 


Saskatchewan to Manitoba. In ponds and slowly 
moving water. 


Submergent leaves finely dissected into thread-like 
segments appearing whorled and crowded at the upper 
nodes. Very soft appearance but firm in texture, 
simple, without petioles. Margins have sharp teeth 
directed forward. 

- 12 

Flower: Aggregation of yellow flowers into heads extending 
above the surface of the water. 

D. Plants with thread-like to ribbon-like leaves scattered singly on 

flexible underwater stems, often paired or bunched toward the stem tips 
Underwater leaves collapse or partly collapse when taken out of water. 

1. Fries' pondweed Potamoqeton fries ii Rupr. 

Range: British Columbia to Manitoba. In relatively 
freshwater ponds and sloughs. 

Plant: Arises from a winter bud with stems compressed; 
thread-like, simple branching produces numerous 
short branches or leaf-tuft which develop into 
winter buds in August to early September. 

Leaves: Uniform, bright green and translucent, 2.5-8.5 cm 
long and 1.5-3.5 mm wide, with broad, blunt, or 
rounded leaf tip, 5-7 nerved with slender, single 
cell band of elongated lacunae or air space tissue 
on each side of midrib. Lateral nerves finer but 
distinct, joining midrib well below tip. 

Winter buds: Terminal on short, lateral branches, narrowly 
fan-shaped, 1.2-2.5 cm long. 

2. narrow-leaf pondweed Potamoqeton strictifol ius Benn. 

Range: British Columbia to Manitoba. 

Plant: Arises from a winter bud with compressed, thread- 
like stems, simple or sparsely and irregularly 
branched producing simple, more or less rigid 
branches in upper axils. 

Leaves: Bright green, firm, often rolled backward from the 
margins, very narrowly linear, 2-7 cm long and 
0.5-2.5 cm wide, rounded tip with short, small, 
abrupt, tooth-like tip, 3-nerved without air space 
tissue, lateral nerves indistinct, joined at midrib 
1-2 mm below tip. 

Winter buds: Terminal as well as axillary on short branches, 
fan-shaped, whitish and more or less fibrous. 

- 13 - 

3. small -leaf pondweed 

Potamoqeton pus ill us L. 



Winter buds: 

British Columbia to Manitoba. In fresh to mildly 
brackish water of sloughs, lakes, or slow-moving 
streams at depths of 0.3 to 1.5 m. 

Usually arises from winter buds without elongated 
rootstocks. Stems very slender and hair-like, 
freely branching with branches terminating in winter 

Linear to bristle-like, 1.0-8.5 cm long and 0.3-2.4 
mm wide, 3-nerved with 3-5 bands of lacunae or air 
space tissue on either side of midrib, lateral nerve 
joins midrib 1-2 mm below tip. 

Terminal, fan-shaped, 0.7-1.8 cm long, inner leaves 
covered by membranous stipules. 

4. sago pondweed 


Potamoqeton pectinatus L. 

British Columbia to Manitoba. 

Submerged, stems slender, slightly reddish, 
many-branched with numerous leaves. 

Narrowly linear, 3-15 cm long and 0.3-0.5 mm wide, 
bristle-like, more or less triangular in 
cross-section, tapering at the apex. No veins 
visible. Stipules fused to the base of the leaves 
for over half their length. 

5. fine-leaf pondweed Potamoqeton filiformis Pers. 



British Columbia to Manitoba. 

Submerged, stems very short, repeatedly branched 
near the base in shallow water with branching 
reduced and stems elongated in deep water. Rhizomes 
creeping and white. 

Linear to thread-like, rounded or blunt at the apex. 
Stipules united at base of leaves for 1 cm. 

6. giant pondweed Potamoqeton vaqinatus Turcz. 
Range: British Columbia to Manitoba. 
Plant: Submerged, stems very coarse and freely branching. 

- 14 - 


Coarse, linear, 5-10 cm long and 1 mm wide, with 
blunt apex. Sheath very conspicuous and broader 
than stems. 

7. flat-stemmed pondweed Potamoqeton zosteriformis Fernald 
Range: British Columbia to Manitoba. 



Submerged with flattened, slightly winged stems 
several times wider than thick, many-branched. 

Linear, 10-20 cm long and 2-5 mm wide, somewhat 
narrowed at the base with 1-3 prominent veins and 
9-35 small secondary veins. Leaf apex rounded with 
a sharp point. 

widgeon grass 



Ruppia maritima L. 

British Columbia to Manitoba. In alkaline ponds, 
lakes, salt springs, and creeks. 

Submerged with slender branching stems. 

Linear, 4-10 cm long and 0.5 mm wide, thread-like 
with blades up to 20 cm long, thick, 1-nerved with 
membranous sheaths at base. 

In an umbel-like cluster with each fruit on a 
separate pedicel . 

Plants with lance-shaped or oval leaves scattered singly on flexible 
underwater stems, often paired or bunched toward the stem tips. Flowers 
are greenish-brown, occurring close together in oblong spikes. 

1. variable-leaf pondweed 

Potamoqeton qramineus L, 


British Columbia to Manitoba along the shores 
lakes, ponds, and streams on muddy, drying 


Many-branched with both submerged and floating leaves 

Form variable, depending on depth of submergence. 
Submergent leaves linear to lance-elliptic to 
oblanceolate in shallow water; 1-13 cm long and 
0.1-1.5 cm wide; sessile with sharp-pointed tip. 
Floating leaves long petioled, ovate-elliptic, 
rounded at base, stipules persistent. 


- 15 - 

Spikes are compact, 1-2.5 cm long when present 

Reproduction: Once established, reproduces vegetatively by runners 
along the surface of the mud flat. 

2. Richardson's pondweed Potamoqeton richardsonii (Benn.) Rydb 






British Columbia to Manitoba in lakes, rivers, 
streams, and irrigation canals and reservoirs. 
Generally in brackish or alkaline waters. 

Can grow in water up to 2 m deep with plants 
stretching to reach the water's surface. Prefers 
standing water or slow-moving streams and irrigation 

All submerged, ovate to lanceolate with 7-33 
prominent nerves with 3-7 very pronounced nerves. 
Leaves 1.5-10 cm long and 0.5-2 cm wide. Base of 
leaf clasps half to three-quarters the circumference 
of stem. 

Spikes are dense, 1.5-3 cm long with prolific seeds 
valued by water fowl. 

Once established, reproduces prolifically by 
underground rhizomes. Rhfzomes exist 6-10 cm under 
the surface of the mud and give rise to a new plant 
every 2-5 cm. 

3. white-stemmed pondweed 

Potamoqeton praelonqus Wulf. 





British Columbia to Manitoba in colder waters of 
lakes and streams. 

Grow in deep water, 2-3 m, with the white stems very 
pronounced when viewed from above. 

All submerged, ovate to lance oblong, 0.5- 
30 cm long, 1-3 cm broad with 3-7 pronounced nerves. 
Base of leaf rounded and may clasp one-third the 
circumference of stem. 

Spike has 6-12 whorls, 3-5 cm long 
prominent beak. 

Seeds with 

Vegetative reproduction occurs from stoutish 
rhizomes. Rhizomes covered with rusty spots and 
grow out in a circle from center point. 

- 16 - 

4. curly-leaf pondweed 

Potamoqeton crispus L. 

British Columbia to Alberta. In thermal heated 
discharges in Alberta. Prefers muddy, calcareous 
and brackish environments. 

Plant: Very aggressive and once established will crowd out 
all other rooted, submerged aquatic plants. Stems 
flattened and very freely branching. 

Leaves: Sessile, oblong to broadly linear, reddish, with 
sharply curved or curly leaf edges. 

Flowers: Spikes very loosely flowered, up to 1.8 cm long with 
flattened seeds. 

Winterbud: Winterbud or overwintering structure hardened and 
bur-like with short, hardened leaves. 

17 - 

Group II. Floating-leaved aquatic plants 

A. Plants with lance-shaped to round-floating leaves, which are notched at 
base. Leaves on flexible, upright to horizontal stems. Flowers white 
or yellow, showy. 

1. spatterdock, yellow pond lily Nuphar luteum (L.) Sibth. & Sin. 



British Columbia to Manitoba, widely scattered along 
pond margins and slowly moving streams 

Leaves and flowers arise on long petioles and 
peduncles from underground rhizome. 

Long petioles flattened above with ridge running 
down midrib. Floating blades thick, dark green, 
0.7-30 cm long and 0.5-25 cm broad. Ovate with 
broad-rounded basal lobes at petiole. 

Flowers are 2.5-4.5 cm high, 5-11 cm wide, deep 
yellow petals with purple at base of petal. 

Very coarse rhizome, 2.5-7 cm thick with pronounced 
leaf scars. 

2. white water lily, northern water lily 

Nymphaea tetraqona Georgi 




Northern British Columbia, Alberta, Saskatchewan, 
and Manitoba. 

Require still or dead water ponds and pools. This 
is the wild relative of the fragrant water lily used 
in water gardens. 

Arise on long petioles from underground rhizomes. 
Blades broadly ovate to obovate thin, 4-9 cm wide 
with a deep sinus at the base of the leaf. 

White, expanding in late afternoon, 2.5-4 cm wide. 

Erect and unbranched. 

3. northern arrowhead 

Saqittaria cuneata Sheldon 

British Columbia to Manitoba. Generally along 
shorelines of lakes. Prefers calcareous or muddy 

- 18 - 




Aquatic or marsh plant with milky juice. Plant 
height and leaf shape variable depending on 
submergence in water. Plants erect (20-40 cm tall), 
simple and frequently branched. 

Emergent leaf blades mostly arrow-shaped with basal 
lobes shorter than the terminal leaf part. 

Conspicuous, mostly unisexual with seeds, white 
petals. Fruiting heads are small balls, 0.8-1.0 cm 
in diameter. 

Slender, produce numerous tubers. 

4. wapato, duck potato 

Saqittaria latifolia Willd. 


British Columbia to Manitoba. Along shorelines and 
sloughs and in slow-moving irrigation canals. 

Perennial, erect, robust, 30-60 cm tall with milky 

Leaf blades arrow-shaped with basal lobes equal to 
terminal leaf part. 

Petals showy white. Fruiting heads over 1.5 cm in 

Coarse, produce numerous tubers used as food by 
waterfowl . 

5. fragrant water lily, white water lily Nymphaea odorata Ait. 




Northern British Columbia to northern Manitoba along 
lake shores and in marsh areas. 

Widely used in water gardens. 

Arise along rhizome on long purplish-green to red 
petioles, blades nearly round, floating, thick and 
usually green above and purplish beneath, 0.5-25 cm 
in diameter. 

Very showy, white and fragrant, open in early 

Horizontal, elongated, freely branched with leaf 

- 19 - 

B. Plants with lance-shaped to round floating leaves, which are tapered to 
slightly notched at the base. Some with thread-like to oval underwater 
leaves. Some with leaves partly growing out of water. 

1. floating-leaf pondweed 

Potamoqeton natans L. 




British Columbia to Manitoba in quiet lakes and 

Prefers still water in protected bays, stems simple 
and sparingly forked. 

Lacks underwater or submerged leaves. Floating 
leaves well developed with petioles longer than 
blades. Blades elliptic to ovate, thick and 
lustrous, 4-9 cm long with rounded bases. 

Spike is compact, 8-14 whorls, 3-5 cm long. 

Vegetative reproduction from red-spotted underground 

2. water smartweed 






Polygonum amphibium var. stipulaceum (Coleman) 

British Columbia to Manitoba in wooded swamps and 
along shores of streams, ditches, irrigation canals, 
and range dugouts. 

Perennial with slender, tough, running rootstocks, 
generally aquatic but variable in habitat and leaf 
characters. May grow on exposed mud flats as water 

Large, oblong to elliptic with long petioles 
floating on surface of water. Underwater stems 
trail . 

Spike-like racemes are solitary or in pairs with 
bright scarlet to pink flowers, 1-3 cm long, 1.5 cm 

Plants trail out into water from shoreline, 
eventually plugging irrigation and drainage ditches. 

- 20 - 

3. broad-leaf water plantain Al isma plantaqo-aquatica L. 





British Columbia to Manitoba on exposed mud flats. 

Generally solitary on mud flats with only aerial 
leaves present. 

On long petiole, somewhat heart-shaped, 5-15 cm long 
with rounded base. 

Inflorescences are erect, 0.5-10 cm tall, with white 

Numerous and nut-like. 

Not a problem for irrigation systems and valuable as 
a wild bird food. 

4. narrow-leaf water plantain 

Al isma gramineum Gmel 




British Columbia to Manitoba in lakes, streams and 
irrigation canals and reservoirs. 

Prefers calcareous to brackish water on muddy shores 
or in irrigation canals. 

Submerged leaves ribbon-like, up to 1 m long, bright 
green. Immersed leaves have slender petiole with 
firm, lanceolate to elliptic blades up to 10 cm 
long, 2 cm wide. 

On erect flowering stalks with white to purplish 

Prolific seed producer. 

Vegetative reproduction from stout corm-like base 
with fibrous roots. 

- 21 - 

Group III. Free-floating aquatic plants 

A. Plants with fine, forked, limp leaves mixed with small roundish bladders 
in flexible underwater stems. Flowers extend out of water. 

1. common bladderwort 

Utricularia vulgaris L. 

British Columbia to Manitoba in deep, quiet ponds 
and pools. 

Plant: Usually floats near the surface, has coarse 

submerged stems crowded with fine, dissected leaves. 

Leaves: Forked or pinnately dissected into coarse, hair- 
like segments. Numerous black bladders, 3-5 mm 
long, scattered among leaves. 

Flowers: Six to 20, produced on slender stalks along the edge 
of the ponds and pools. Bright yellow with brown 

Winterbuds: Buds are 1-2 cm long, of dense minute leaves crowded 
into a greenish-black hairy structure similar to elk 

B. Plants small, free-floating, usually in shade of marsh plants 
Reproduction is chiefly by offshoots from mature plants. 

1. star duckweed 





Lemna trisulca L. 

British Columbia to Manitoba in cool spring-fed 
ponds and pools. 

Minute aquatic plants float in the water in dense 
tangled mats lacking true stem, leaf tissue and 
root. Several plants may remain attached to each 

Leaf-like structure on flat thai 1 us (frond), oblong 
to oblong-lanceolate, 0.6-1 cm. 

Plants reproduce by budding, producing new fronds at 
the edge of the parent. 

By minute bulblets that form in the fronds in the 
fall and sink to the pond bottom. Rise in the 
spring as the water warms and sunlight penetrates 
the depths. 

- 22 - 

little or small duckweed 

Lemna minor L. 




British Columbia to Manitoba in standing water. 

Common in quiet water and in among cattails and 
other emergent vegetation; forms bright green mats 
or carpets. 

Fronds round, 2-5 mm in diameter, thick, bright 
green, small rootlike structures hang from underside 
of fronds. 

Forms rosettes of small fronds that separate slowly 
to produce new plants. 

3. larger duckweed, water flaxseed Spirodela polyrhiza (L.) Schleid 




British Columbia to Manitoba along stream margins 
and in pools and ponds. 

Has several root-like structures hanging down from 
broad 3-8 mm plant. 

Fronds round to obovate, thick, dark green above 
with reddish to purple underside, 5-11 nerved with 
6-18 root-like structures. 

Plants reproduce by budding, producing new fronds at 
the edge of the parent. 

Overwintering: From minute bulblets formed in the fall that sink to 
the bottom sediments to overwinter. Rise to surface 
when the water warms in the spring. 

- 23 - 

Group IV. Emergent aquatic plants 

A. Plants with rather stiff, upright, or upshooted leafless stems, or with 
long narrow leaves coming from lower parts of stems, growing in clumps 
or patches on the canal or lake bottom and coming up year after year 
from rootstocks or creeping rhizomes. Flowers usually individually 
inconspicuous in greenish, yellowish, or brown clusters. 

1. softstem bulrush 




Scirpus val idus Vahl. 

British Columbia to Manitoba, very common and 

Tufted or stoloniferous perennial on wet soil, 
usually growing in up to 1 m of water. Stems thick 
(0.8-2.5 cm) at base, light green, soft and spongy. 

True leaves lacking, culms or stems rounded in 
cross-section, 0.5-2.5 m tall. 

Spikes on compound inflorescence ascending at top 
and spreading and open at bottom, 1-6 cm long, each 
bearing several short peduncled spikelets. 

Reproduces extensively by stout rhizomes covered 
with fibrous roots. 

2. hardstem bulrush Scirpus acutus Muhl. 



British Columbia to Manitoba, widespread in hard 
water areas. 

Perennial growing on wet soil. Stems or culms 3-10 
mm thick at base, dark olive green, firm in texture 
growing to 0.5-3.0 m. Stems hard to crush. 

True leaves lacking, stems or culms rounded in cross 

Spikes as compound inflorescence, rather stiffly 
ascending and divergent, 1-8 cm long, each bearing 
1-5 spikelets. 

Reproduction: From thick, spongy rhizomes with swollen roots. 

- 24 

3. wire rush, baltic rush 

Juncus balticus Willd, 




British Columbia to Manitoba in salt or brackish 

water on sandy shores. 


Smooth perennial herb looking like grasses or 
sedges, 20-80 cm tall, leaves arising at intervals 
along creeping rootstock. 

Stems of culms in small tufts or singly channelled, 
more or less rounded with basal leaves reduced to 
loose brownish sheaths. 

Inflorescence is loosely forked and diffusely 
branched, 2-4 cm long, purplish brown in color. 

Plants appear as rows arising from underground 

soft rush 




Juncus effusus L. 

British Columbia to Manitoba with plants highly 
variable in response to regional temperatures and 
water conditions. 

Has stems or culms borne in large clumps, generally 
firm, 0.4-2 m tall. Very fine ridges or furrows 
along green stem. 

Generally lacking. 

Inflorescence many-flowered, forking and densely 
compact, greenish to brown in color. 

Plants appears as clumps, densely packed on stout 
underground rhizome. 

5. needle rush, slender spikerush 

Eleocharis acicularis R. & S 



British Columbia to Manitoba in shallow, 10-12 cm 
clear fresh water. 

In tufted carpets from underground, fine rhizomes 
and stolons. Grows beneath water but can stand 
short periods of exposure to air. 

Culms or stems very fine, angular and furrowed, 
ranging from 2-10 cm long. 




Spikelets flattened, linear, and narrowly rounded, 
2-7 mm long. Flowers 3-15, very fine and delicate, 
yellow turning reddish brown at maturity. 

Extensive from stolons. 

Plant has been looked at as potential carpeting or 
seeded grass-like vegetation for canals and 
ornamental water gardens. 

6. broad-leaf cattail Typha 1 at i folia L. 






British Columbia to Manitoba appearing in almost any 
wet place and usually first invader in newly 
excavated ditches and dugouts. 

Marsh or aquatic herb with coarse creeping rootstock 
spreading extensively. Stems stout, 1-2 m tall. 

Leaves linear, 6-25 mm broad and extending beyond 
stem, pale green to grayish-green in color. 

Long, mace-like, very dense cylindrical spike termi- 
nating at end of stem. Top part the male flowers, 
yellow in color from pollen; lower portion has 
female flowers, green turning brown at maturity. 

Underground stems are so extensive that a patch of 
cattails an acre in extent may only be three to four 

7. narrow-leaf cattai 

Typha auqustifolia L. 




Manitoba, chiefly in strongly basic or alkaline 
water. Plants have not been seen west of Manitoba 

Looks like typical cattail, but leaves are much 

Few (less than 10), convex on the back, green, 
3-8 mm wide. 

In long, narrow, dense cylindrical spike at end of 
stem. Top part male flowers separated by short 
interval. Lower portion female flowers, reddish 

- 26 

8. big bur reed 




Sparqanium eurycarpum Engelm. 

British Columbia to Manitoba along mucky lake 

Marsh or aquatic perennial plants arising from 
underground rootstocks. Stems stout, erect, 
50-150 cm tall. 

Stiffish, flat with a slight keel or ridge, 6-12 mm 
broad. Longitudinal and cross veins very evident in 
leaves give a mesh-like pattern. 

Unisexual, form dense, hard spherical heads or small 

Extensively from underground rootstock or rhizome. 

9. floating-leaf bur reed 

Sparqanium fluctuans (Morong) Robinson 



British Columbia to Manitoba in deep or shallow 
water in isolated pockets. 

Slender aquatic with stems and leaves floating, up 
to 1.2 m long. 

Very elongated 1.5-5 mm broad, convex with the 
underside of the leaf appearing mesh-like and the 
top side opaque. 

Male heads 1-6, close together on upper part of 
inflorescence, female flowers on lower portion, 
1-2 cm in diameter when mature. 

B. Plants with upright or upshooted stems with grasslike leaves on two 
sides (one plane). Most reproduce by creeping rhizomes or rootstocks 
but a few new plants grow each year from seed. 

reed phragmites 


Phragmites communis Trin. 

British Columbia to Manitoba along fresh and 
alkaline marshes, pond margins and irrigation and 
drainage canals. 

Very large perennial up to 4 m tall with long, 
creeping rhizome. Stems generally 1.5-3 m tall, 

- 27 - 


Leaf blade flat, 1-6 cm wide, smooth, 15-60 cm long; 
leaf sheaths overlap. 

Inflorescence 10-40 cm long, dense with branches 
ascending to nodding, tawny to purplish color 
flowers; long silky hairs on spikelet give a silky 
appearance to flowerhead. 

2. wild rice 





Zizania aquatica L. 

Not native to British Columbia and Alberta but 
introduced as water fowl food. Native to 
Saskatchewan and Manitoba. 

Tall aquatic annual grasses with 1-2 m stems. 

Leaf blade flat, 4-15 mm wide with long sheaths. 

Inflorescence is large, erect panicle (compound and 
branched flower cluster) 30-60 cm long. Lower 
branches ascending bearing male flowers. Upper 
branches erect bearing female flowers. 

Used extensively for food by water fowl and humans. 

wild millet, barnyard grass 

Echinochloa punqens (Poir.) Rydb 





Native plant of stream banks and flats in 
southeastern Alberta and southwestern Saskatchewan. 
Spread into cultivated fields and along roadsides. 

Coarse annual grass with thick stems (culms), simple 
or branching at base, erect from 30-80 cm tall. 

Leaves long, 5-15 mm broad, smooth with compressed 

Inflorescence is stout, open panicle of racemes dark 
purple to greenish with lower branches spreading 
with bristles in axis of inflorescence. 

Japanese millet, E_^ crusqall i var. frumentacea 
(Roxb.) Wight, was introduced as forage grass and 
used as chicken feed. Escaped to roadside ditches 
and abandoned fields. 


4. reed canary grass 

Phalaris arundinacea L. 




British Columbia to. Manitoba along shorelines, in 
swales and sloughs, and in irrigation and drainage 

Robust perennial with creeping rhizomes. Stems 
(culms) smooth without hairs, 60-150 cm tall. 

Leaf blade 10-30 cm long, 6-15 mm wide. 

Dense, of spike-like panicles (or branched flower 
cluster) with spikelets, 5-6 mm long in club-like 
masses, pale purple in color. 

Once used as forage grass along irrigation canals 
but too aggressive. Now a serious problem. 

5. slough grass 




Bechmannia syziqachne (Steud.) Fernald 

British Columbia to Manitoba in marshes and along 
irrigation and drainage ditches. 

Coarse annual grass growing on low, wet ground, 
stems stout, 30-100 cm tall, light green in color, 
solitary or tufted. 

Leaf blades 10-25 cm long and 5-8 mm broad, rough to 

Inflorescence narrow, crowded in interrupted flower 
head composed of numerous ascending one-sided 

Seeded to stabilize prairie sloughs. 

Plants with upright stems with grasslike leaves on three sides. Stems 
usually stand close to each other in colonies with leaves interlocked. 
Flowers occur between scales, which usually overlap in several rows to 
form spikelets. Most reproduce year after year from rootstocks. 

1. beaked sedge 

Carex rostrata Stokes 

British Columbia to Manitoba along wet shores in 
shallow water and in swamps. 

- 29 




Culms or triangular stems thickened and spongy at 
base. Plants 50-100 cm tall, perennial herbs. 

Three-ranked, long and narrow, 2-10 mm, pale green 
with closed sheaths. Prominent cross markings 
between veins. 

Monoecious with 2-4 staminate spikes on short 
stalks, upper part of stem. Pistillate flowers on 
lower stem, cylindrical, dense, with nuttel encased 
in beaked sac. 

Horizontal rhizomes and stolons, smooth and angled, 
give rise to a number of upright stems. 

Seeds important to wildlife, plants grazed by 

Plants with upright, sprawling, or horizontal stems with singly placed, 
non-grasslike, lance-shaped, untoothed leaves. Flowers clustered at the 
end of stems. 

1. water smartweed 






Polygonum amphibium var. stipulaceum (Coleman) 

British Columbia to Manitoba in wooded swamps and 
along shores of streams, ditches, irrigation canals 
and range dugouts. 

Perennial with slender, tough, running rootstocks, 
generally aquatic but variable in habitat and leaf 
characters. May grow on exposed mud flats as water 

Large, oblong to elliptic with long petioles 
floating on surface of water. Underwater stems 
trail . 

Spike-like racemes are solitary or in pairs with 
bright scarlet to pink flowers, 1-3 cm long, 1.5 cm 

Plants trail out into water from shoreline, 
eventually plugging irrigation and drainage 

- 30 - 

2. marsh smartweed 





Polygonum coccineum Muhl . 

British Columbia to Manitoba in marshes and sloughs, 
along irrigation and drainage canals. 

Perennial with stout creeping rootstock, generally 
found in marsh areas. Stems upright, simple, 30- 
100 cm tall. 

Short-petioled, broadly to narrowly lanceolate, 
commonly pubescent, with leaf tapering to point. 

Racemes 1 or 2, spike-like slenderly cylindrical, 
3-12 cm long, scarlet to pink in color. 

Plants take over moist areas and then encroach into 
cultivated fields. 

- 31 - 


The following references are suggested as sources of general identification 
and taxonomy of aquatic vegetation in North America and Canada. 

Arber, A. 1920. Water plants. A study of aquatic angiosperms. Reprinted 
1963 by Wheldon and Wesley, Ltd., Codicote, Herts, England, and Hafner 
Publishing Co., New York, NY. 

Burland, G. R. (ed.) 1989. An identification guide to Alberta aquatic 
plants. Alta. Environment, Pesticide Management Branch, Edmonton, 

Cowardin, L. M., Golet, F. C, and LaRoe, E. T. 1979. Classification of 
wetlands and deepwater habitats of the United States. Office of 
Biological Services, Fish and Wildlife Service, U.S. Dept. Interior, 
Washington, DC. 

Fassett, N. C. 1966. A manual of aquatic plants. The University of 
Wisconsin Press, Madison, WI. 

Fernald, M. L. 1950. Gray's manual of botany. American Book Company, 
New York, NY. 

Moss, E. H. 1959. Flora of Alberta. University of Toronto Press, 
Toronto, Ontario. 

Muenscher, W. C. 1944. Aquatic plants of the United States. Comstock 
Publishing Co., Inc., Cornell University, Ithaca, NY. 

Sculthorpe, C. D. 1967. The biology of aquatic vascular plants. Edward 
Arnold (Publishers) Ltd., London, England. 

Tarver, D. P., Rodgers, J. A., Mahler, M. J., and Lazor, R. L. 1979. 

Aquatic and wetland plants of Florida. Bureau of Aquatic Plant Research 
and Control, Dept. of Natural Resources, Tallahassee, FL. 

Welch, P. S. 1952. Limnology. McGraw-Hill Book Co., Inc., New York, NY. 

Wetzel, R. G. 1975. Limnology. W. B. Saunders Co., Toronto, Ontario. 

Winterringer, G. S., and Lopinot, A. C. 1966. Aquatic plants of Illinois. 
Dept. of Registration and Education, 111. State Museum Div. and Dept. of 
Conservation, Div. of Fisheries, State of Illinois, Chicago, IL. 

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